I honestly think Bones just wanted to do a Giant Robot battle in Soul Eater, even if it came off extremely ridiculous. And it did. Hell, the characters thought this was ridiculous (even Arache of all people).
Though, from the look of things, next week goes back into normal seriousness. I wasn't too impreased with Black Star's fight, though I don't think anyone was particularly looking forward to how it was going to end. In anycase, we only got a couple more episodes to go.